Seal arrangement for filter element; filter element assembly; and, methods

ABSTRACT

A filter cartridge arrangement is provided which includes a media pack comprising Z-filter media, a preform and a housing seal member. Improvements in the preform and seal member are described which include: a single beveled surface of the seal member to facilitate installation; and, an inside region of the seal member having a tip adjacent in inwardly directed lip of the preform, to control flash during molding. A variety of media pack configurations and features are described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/639,464, filed Jun. 30, 2017. U.S. application Ser. No. 15/639,464 isa continuation of U.S. application Ser. No. 14/611,604 filed on Feb. 2,2015. U.S. application Ser. No. 14/611,604 is a continuation of U.S.application Ser. No. 13/854,316, filed on Apr. 1, 2013, and granted asU.S. Pat. No. 8,945,268 on Feb. 3, 2015. U.S. application Ser. No.13/854,316 is a continuation of U.S. application Ser. No. 12/084,730,deposited on May 7, 2008 (371(c) date of Mar. 30, 2009), and granted asU.S. Pat. No. 8,409,316 on Apr. 2, 2013. U.S. application Ser. No.12/084,730 is a U.S. National Stage of PCT international patentapplication No. PCT/US2006/043836, filed Nov. 8, 2006, which claims thebenefit of U.S. Provisional Patent Application Ser. No. 60/735,650,filed Nov. 9, 2005. To the extent appropriate, a claim of priority ismade to each of the above disclosed applications. The above disclosedapplications are incorporated herein by reference.

The present application includes disclosure discussed in U.S.Publication US 2005/0166561 A1, published Aug. 4, 2005, PCT PublicationWO 05/63361, published Jul. 14, 2005, U.S. Pat. No. 6,190,432 andEuropean Patent EP 1 159 052, each of which is incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to air cleaners with removable andreplaceable, i.e., serviceable, filter element components. Althoughother applications are possible, the invention described is particularlyuseful in air cleaners for use in filtering intake air for engines (usedfor example in: vehicles, construction, agricultural and miningequipment; and, generator systems). The invention specifically concernsseal arrangements provided on serviceable filter elements, for such aircleaners. The invention also concerns methods of assembly and use.

BACKGROUND

Air streams carry contaminant material therein. In many instances, it isdesired to filter some or all of the contaminant material from the airstream. For example, air flow streams to engines for motorized vehiclesor for power generation equipment, construction equipment or otherequipment, gas streams to gas turbine systems and air streams to variouscombustion furnaces, carry particulate contaminant therein. It ispreferred for such systems that the selected contaminant material beremoved from (or have its level reduced in) the air or gas. A variety ofair filter arrangements have been developed for contaminant reduction.In general, however, continued improvements are sought.

The techniques described herein are for variations in the sealarrangements of the types described in U.S. Publication US 2005/0166561A1, published Aug. 4, 2005, PCT Publication WO 05/63361, published Jul.14, 2005, U.S. Pat. No. 6,190,432 and European Patent EP 1 159 052, eachof which is incorporated herein by reference.

SUMMARY

According to the present disclosure a filter element is provided, foruse in air filtering. Typically, the filter element comprises a mediapack including opposite inlet and outlet ends (or faces). The media packtypically defines: a set of inlet flutes open at the inlet end of themedia pack to passage of air to be filtered therein, the inlet flutestypically being closed at a location within a distance of 10% of thetotal length of the inlet flutes from the outlet end of the media pack;and, a set of outlet flutes closed to passage of air to be filteredtherein at a distance within 10% of the total length of the inlet flutesfrom the inlet end of the media pack and open the passage of filteredair therefrom at the outlet end of the media pack. The media pack istypically closed passage of air therethrough, in between the inlet andoutlet ends, without filtering flow through the media pack. The elementfurther includes: a preform positioned adjacent a first one of the inletand outlet ends of the media pack; and, a seal arrangement mounted onthe preform.

In certain preferred applications, the media pack is a coiled z-filtermedia arrangement; and, the seal arrangement comprises foamedpolyurethane. The media pack can have a variety of shapes andconfigurations. Two examples depicted are: an oval perimeter shape(periphery), for example having a racetrack perimeter or cross-sectionalshape; and, a cylindrical shape having a circular perimeter (periphery)or cross-sectional shape. A variety of alternate shapes, are possible.

The techniques described herein were developed to provide improvementsin such arrangements as those described in U.S. Publication US2005/0166561 A1, published Aug. 4, 2005 and PCT Publication WO 05/63361,published Jul. 14, 2005, U.S. Pat. No. 6,190,432 and European Patent EP1 159 052, incorporated herein by reference. The improvements describedherein can be applied in other applications, as well.

BRIEF DESCRIPTION OF THE DRAWINGS I. Selected Figures from US2005/0166561 and PCT WO 05/63361, FIGS. 1-25

FIG. 1 is a side elevational view of a filter element according to anexample from U.S. Publication US 2005/0166561 A1, published Aug. 4, 2005and PCT Publication WO 05/63361, published Jul. 14, 2005.

FIG. 2 is a top view of the filter element component of FIG. 1.

FIG. 3 is a cross-sectional view taken along line 3-3, FIG. 2.

FIG. 4 is an enlarged fragmentary view of a portion of FIG. 3.

FIG. 5 is an enlarged, perspective view of a component used in thefilter element of FIG. 1.

FIG. 6 is a cross-sectional view of the component of FIG. 5, taken alongline 6-6 thereof.

FIG. 7 is a side elevational view of a filter element according to asecond example from U.S. Publication US 2005/0166561 A1, published Aug.4, 2005 and PCT Publication WO 05/63361, published Jul. 14, 2005.

FIG. 8 is a top view of the element shown in FIG. 7.

FIG. 9 is a cross-sectional view of the arrangement depicted in FIG. 8,taken along line 9-9 thereof.

FIG. 10 is an enlarged, fragmentary, view of a portion of FIG. 9.

FIG. 11 is a fragmentary schematic, cross-sectional view of a moldarrangement useable to form a seal component of the arrangement depictedin either FIG. 1 or FIG. 7.

FIG. 12 is a schematic cross-sectional view of the mold of FIG. 11,depicted with a pool of non-cured polymeric seal material therein.

FIG. 13 is a view of the mold of FIG. 12 with certain pre-formed filterelement componentry positioned therein.

FIG. 14 is a view of FIG. 13 with a media component positioned therein.

FIG. 15 is a view of FIG. 14, with the seal material foamed andsubstantially cured.

FIG. 16 is a view of preform and media pack component in a moldaccording to the process of FIGS. 11-15.

FIG. 17 is an optional end piece useable in the component of FIG. 1.

FIG. 18 is a cross-sectional view of the optional piece of FIG. 1.

FIG. 19 is a fragmentary, schematic, perspective view of z-filter mediauseable in arrangements according to U.S. Publication US 2005/0166561A1, published Aug. 4, 2005 and PCT Publication WO 05/63361, publishedJul. 14, 2005.

FIG. 20 is a schematic, cross-sectional view of a portion of the mediadepicted in FIG. 19.

FIG. 21 is a schematic view of examples of various corrugated mediadefinitions.

FIG. 22 is a schematic view of a process for manufacturing mediaaccording to U.S. Publication US 2005/0166561 A1, published Aug. 4, 2005and PCT Publication WO 05/63361, published Jul. 14, 2005.

FIG. 23 is a schematic cross-sectional view and optional end dart formedia flutes useable in arrangements according to US 2005/0166561 andPCT WO 05/63361.

FIG. 24 is a schematic perspective view of a media material useable inthe filter elements of FIG. 1 and FIG. 7.

FIG. 25 is a schematic view of a system using an air cleaner having afilter cartridge component according to U.S. Publication US 2005/0166561A1, published Aug. 4, 2005 and PCT Publication WO 05/63361, publishedJul. 14, 2005.

II. Selected Figures from 6,190,432 and EP 1 159 052, FIGS. 26-27

FIG. 26 is a perspective view of a filter cartridge in accord with thedescription of U.S. Pat. No. 6,190,432 and European Patent EP 1 159 052.

FIG. 27 is an enlarged fragmentary cross-sectional view of a sealportion of the cartridge of FIG. 26.

III. Figures Depicting Selected Improved Arrangements, FIGS. 28-40 A.Example Chamfered or Beveled Seals, FIGS. 28-31

FIG. 28 is a top plan view of a molded seal member portion useable in anarrangement in accord with selected ones to the previously describedfilter arrangements.

FIG. 29 is a cross-sectional view taken along line 29-29, FIG. 28.

FIG. 30 is an enlarged fragmentary view of a portion of FIG. 29.

FIG. 31 is a cross-sectional view analogous to FIG. 29, of an alternatevariation in the depleted seal member.

B. Modifications Involving a Preform Central Projection to FacilitateMolding of the Seal Member, FIGS. 32-40

FIG. 32 is a schematic side elevational view of a filter cartridgeincluding a seal with a modified preform in accord with principlesdescribed herein and depleting an optional end piece thereon.

FIG. 33 is a schematic cross-sectional view of media pack and sealportions of the cartridge depicted in FIG. 32; the cross-section of FIG.33 being taken along a long axis.

FIG. 34 is a second schematic cross-sectional view of the cartridgedepicted in FIG. 32; the cross-section of FIG. 34 being taken along ashort axis.

FIG. 35 is an enlarged fragmentary cross-sectional view of a portion ofFIG. 34.

FIG. 36 is a top plan view of a preform component usable in the filtercartridge of FIGS. 32-35.

FIG. 37 is a cross-sectional view taken along line 37-37, FIG. 36.

FIG. 38 is a cross-sectional view taken along line 38-38, FIG. 36.

FIG. 39 is a cross-sectional view taken along line 39-39, FIG. 36, anddepicted inverted as it would when placed in a mold for a molding stepforming a seal.

FIG. 40 is a cross-sectional view of an overmolded seal member thatwould be formed on the preform of FIG. 37 to form the cartridge FIG. 32.

DETAILED DESCRIPTION I. General Information

The present disclosure relates to filter elements useable in air cleanerassemblies. In general, the preferred filter elements of concern hereinare those in which: (a) the media of the elements comprises a firstfluted (typically folded or corrugated) sheet of media attached to asecond sheet of media (typically a flat media or nearly flat media) toform a single facer; and (b) in which the single facer combination iseither wound or stacked, to create a media arrangement comprising aplurality of inlet flutes open at an inlet end or face of the filtermedia and closed at or near (typically within 10% of the total length ofthe inlet flutes of) the outlet and/or face of the media; and, aplurality of outlet flow flutes sealed closed at or near the inletand/or face of the media (i.e., typically within 10% of the total lengthof the outlet flutes of the inlet and/or face), and open at the outletend or face of the media. Typically the media pack is also closed toflow therethrough, entering the inlet face and exiting the outlet face,of air which has not been filtered by passage through the media of themedia pack.

Such media arrangements are well known and are described for example inU.S. 2005/0160561 A1 published Aug. 4, 2005; PCT WO 05/63361 publishedJul. 14, 2005; U.S. Pat. No. 6,190,432 and EP 1 159052; the completedisclosures of these four U.S. patents being incorporated herein byreference. Herein, such media will sometimes be referred to as z-filtermedia; and, media packs formed from such media as z-filter media packs.

Many variations of such media can be used, with the principles accordingto the present disclosure. For example, the end seals of the flutes(flute seals) can be provided in a variety of ways, including throughutilization of sealant beads; darting, folding or other arrangements fordistorting the shape of the flute at the end and/or closing and sealingthe flute ends; and through combinations thereof. Not all flutes need tobe sealed closed in the same way. The particular approach to flutesealing is generally a matter of choice, not specifically related to thegeneral principles described herein (except as indicated) in connectionwith provision of seals between the serviceable filter element and ahousing or housing component, in use.

Another variable is the specific shape of the flutes. Tapered flutes inaccord with PCT Application No. WO 97/40918 and PCT Publication NumberWO 03/47722 and other flute shapes can be used, with arrangementsaccording to the principles disclosed. Of course, straight (non-tapered)flutes can, and often will, be used.

Another variable with respect to the media arrangement, is whether themedia is configured in a “coiled” arrangement or a “stacked”arrangement. The principles described herein will typically be appliedin connection with “coiled” arrangements, for reasons which will beapparent from the following discussions. However, certain of theprinciples could be applied in connection with arrangements that arestacked.

Herein the term “coiled” and variants thereof, when used to refer to amedia pack form from z-filter media, is meant to refer to a media packformed by coiling a single combination strip of media or single facer,made from a strip of corrugated media secured to flat or nearly flatsheet (the combination being a single facer), in order to form the mediapack. Such coiled media can be made in a variety of shapes including:round or cylindrical; oval, for example racetrack; square; orrectangular with rounded corners; and, they can even be configured inconical or similar arrangements. Examples of selected ones of these aredescribed in U.S. Pat. No. 6,350,291 and U.S. provisional applicationSer. No. 60/467,521, filed May 2, 2003, the complete disclosures ofwhich are incorporated herein by reference.

Herein the term “stacked arrangements” and variants thereof generallyrefers to media packs that are not formed from a single combinationstrip of media that is coiled, but rather to media packs formed from aplurality of strips of media or single facer (corrugated media securedto flat or nearly flat media); the strips being secured to one anotherin a stack or block form. Stacked arrangements are described for examplein U.S. Pat. No. 5,820,646, at FIG. 3, incorporated herein by reference.

In general, z-filter media pack arrangements as described, are used inserviceable filter elements, i.e., filter elements that are removableand replaceable with respect to an air cleaner in which they are used.Generally, such z-filter media packs are provided with sealingarrangements for engagement with portions of air cleaner parts such as ahousing, in use. Herein, such seals are referred to as “air cleanerseals” or “housing seals,” or by variants thereof. A variety of such aircleaner seals are known. One type, involving an outside or outwardlydirected radial seal, is described in U.S. 6,350,291 at Ref #250, FIG.5.

Other types of seals useable with z-pack media are axial pinch seals, asdescribed for example in U.S. Pat. Nos. 6,348,085; 6,368,374 and U.S.Publication US 2002/0185007 A1, incorporated herein by reference; and,internally directed radial seals, as described for example in U.S.Provisional 60/457,255 filed Mar. 25, 2003 at FIG. 12, the completedisclosure of which is incorporated herein by reference.

II. The Arrangements of US Publication 2005/0166561 A1 (Published Aug.4, 2005 and PCT Publication WO 05/63361 (Published Jul. 14, 2005)

The techniques described herein are applicable in conjunction with theprinciples described in US 2005/0166561 and PCT WO 05/63361, each ofwhich is incorporated by reference. Therefore, before the improvementtechniques of the present application improvement are described, generalprinciples of US 2005/0166561 and WO 05/63361 are described.

A. An Example Element, FIGS. 1-6

The reference numeral 1, FIG. 1, generally depicts a serviceable filterelement (air filter cartridge) according to the disclosures of US2005/0166561 and WO 05/63361. The filter element 1 depicted, comprises az-filter media pack 2 having an air cleaner seal arrangement (housingseal arrangement) 3 positioned thereon.

Again, herein, the term “air cleaner seal arrangement”, “housing sealarrangement” and variants thereof is generally meant to reference a sealarrangement 3 provided on a serviceable filter element or cartridge 1 insuch a manner that, when the filter element 1 is installed in an aircleaner for use, the seal arrangement 3 provides for an air seal withappropriate componentry or portions of air cleaner, typically an aircleaner housing. The term “serviceable element” in this context, ismeant to refer to a filter element 1 which is removable and replaceablewith respect to other portions of an air cleaner.

The particular air cleaner seal arrangement 3 depicted comprises anoutside radial seal member. By the term “outside radial seal member” inthis context, it is meant that the surface 6 which forms a seal with anair cleaner component, in use, is directed radially outwardly, ratherthan radially inwardly with respect to the portion of the serviceablefilter element 1 on which it is mounted.

In general, during operation, air flow through the z-filter media pack 2is shown by inlet arrow 9 and exit arrow 10. It is a characteristic ofz-filter media packs, that air flow therethrough is generally such thatthe inlet flow arrow and exit flow arrow are generally parallel to oneanother. That is, the only turns the air needs to make in passagethrough the element 1 are minor turns in flow through media pack 2,since the air flow flutes are generally parallel to one another, andparallel to the direction of inlet and outlet flow. It is noted that anopposite direction of air flow to that shown by arrows 9 and 10 ispossible, but this particular direction of air flow shown, in use, isadvantageous. When constructed and oriented for use in this manner, themedia pack 2 has an inlet end or flow face 15 and an opposite exit endor flow face 16.

For the example shown, the inlet flow face 15 and exit flow face 16 areeach substantially planar and are substantially parallel with oneanother. Although alternate arrangements are possible, the principlesdisclosed herein are particularly well considered for this application.

FIG. 2 is a top plan view of filter element arrangement 1. Referring toFIG. 2, the z-filter media 2 and seal arrangement 3 are provided with anoval outside perimeter shape, in this instance corresponding to twosimilar, opposite, curved ends 20, 21 spaced apart by two opposite,generally sides, 22, 23. Herein this specific oval configuration willgenerally be referred to as a “racetrack” shape with sides 22, 23 beinggenerally straight. Racetrack shaped z-filter media pack elements aredescribed in the prior art, for example, in U.S. Pat. No. 6,350,291 atFIG. 10. It will be seen that many of the principles of the presentdisclosure can be applied in elements having media packs with alternateperipheral shapes, for example circular, as described herein below.Another variation in the oval shape would one in which the oppositesides are not straight, but are curved somewhat, with less curvaturethan the ends. Another shape which is possible, is a shape which has twopairs of opposite, generally straight, sides which may or may not have aslight curvature to them, with four substantially curved corners. Anexample of this type of element is described in U.S. provisionalapplication 60/457,255, in FIG. 22, the complete disclosure of which isincorporated herein by reference.

The various shapes identified in the previous paragraph, indicate thatthe principles discussed herein can be applied to a wide variety ofcoiled shapes, not just the ones shown in the figures.

Referring to FIG. 1, the filter element 1 includes an optional end pieceor skid skirt 30 thereon, at an opposite end of the media 2 from theseal arrangement 3. The optional end piece or skid skirt 30 can be usedto provide engagement between element 1, and structure in a housing,during use, to facilitate installation. Examples of such end pieces areshown and described, in PCT Publication number WO 03/095068, publishedNov. 20, 2003, at FIGS. 4 and 8, the complete disclosure of PCTpublication WO 03/095068 being incorporated herein by reference. Theoptional end piece 30 is discussed further below, in association withdescription of FIGS. 17 and 18.

Referring to FIG. 2, seal arrangement 3 comprises: a rigid preform partor insert 35; and, a molded seal component 36. By the term “preformpart” and variants thereof, as used in this context herein, it is meantthat part 35 is formed prior to formation of the molded seal component36 to form the seal arrangement 3. Indeed, in a typical manufacturingprocess for filter element 1, as described below: media pack 2 would bepreformed; part 35 would be preformed; and, the two parts (2, 35) wouldbe placed together in a mold, for formation of the molded seal component36. Herein, the particular molded seal component 36 depicted issometimes referred to as an “overmold,” or by variants thereof.

Attention is now directed to FIG. 3. FIG. 3 is a cross-sectional viewtaken along line 3-3, FIG. 2. The cross-section of FIG. 3 is through theshorter or narrower dimension of the element 1, FIG. 1. However, similarfeatures will be viewable, if the cross-section were taken along thelonger axis, i.e., line Y-Y, FIG. 2.

The media pack 2, FIG. 3, is a coiled media pack. In general the mediapack 2 comprises a corrugated media sheet secured to a flat or nearlyflat sheet to form a strip or single facer, which is itself coiled inthe configuration shown. Thus, the media pack 2 comprises a single stripof the corrugated sheet/flat or non-corrugated sheet, or single facer,coiled and configured as shown. In FIG. 2, although the media pack isshown schematically, the outer three coils are indicated. Referring toFIG. 1, the outside tail end of the outer most coil is shown at 37. Forthe embodiment shown, tail end 37 is sealed and secured in position, bya hot melt sealant strip 38, although alternatives are possible.

Referring again to FIG. 3, it is noted that there is no center board,center gap, center piece or center seal schematically shown in the mediapack 2. The media pack 2 is simply shown schematically with respect tothis point. Center boards can be used, for example as described in U.S.Pat. No. 6,348,084, incorporated herein by reference. Interdigitatedcenter strips can be used, for example as described in U.S. ProvisionalApplication Ser. No. 60/467,521, filed May 2, 2003. Center seals canalso be used, for example as described in U.S. Provisional ApplicationSer. No. 60/467,521, filed May 2, 2003. No specific choice from amongthese, and variants, is meant to be indicated with respect to FIG. 3.

Referring to FIG. 3, the preform part 35 depicted includes threesections generally comprising: housing seal support section 40; mediaengagement periphery or skirt 41; and, media face cross-piecearrangement 43.

Attention is directed now to FIG. 4. FIG. 4 is a fragmentary enlargedview of a portion of FIG. 3. In FIG. 4 it can be seen that no portion ofpreform 35 extends around the outer periphery or side 2 a of the mediapack 2. This will be preferred, for arrangements according to thepresent disclosure, although alternates are possible. For the particulararrangement depicted in FIG. 3, media engagement portion 41 includes anedge 45 which is brought into engagement with flow face 16 of thez-filter media pack 2 and which does not project to, or beyond, an outerperimeter edge 16 a of flow face 16. The particular preform 35 depictedincludes a small ridge 45 a, FIG. 6 which projects slightly into mediapack 2. Preferably ridge 45 a is no greater than 1 mm and comes to afine point, to help contain flow of rising urethane, during formation ofthe seal component 36, and desirably from extending across flow face 16.

As described above in reference to FIG. 3, it is noted that theparticular z-filter media pack 2 depicted comprises a coiled mediaarrangement. In FIG. 4, the outer three coils 46 a, 46 b and 46 c areformed. The ends of coils 46 a, 46 b and 46 c, adjacent surface 16, areshown comprising ends folded or darted closed at 47. Such folding ordarting is described, for example, in U.S. Provisional Application Ser.No. 60/467,521, filed May 2, 2003, incorporated herein by reference.

Referring still to FIG. 4, molded seal component 36 is positioned with aportion 48 overlapping and sealing a joint 49 where preform part 35engages flow surface 16 of the media pack 2. In particular, the depletedmolded seal component 36 includes a portion 51 which extends beyond thejoint 49 in a direction away from flow face 16 (toward opposite flowface 15, FIG. 3) a distance of at least 5 mm, preferably at least 8 mm,and typically a distance within the range of about 9 mm to 18 mm,inclusive.

In general, portions 48 and 51 of the molded seal component 36, providethen, for a sealing between the media pack 2 and the preform part 35 atthis location, and also for sealing around and against media pack 2,adjacent face 16, to inhibit undesired, contaminated, air flow at thisregion.

Referring to FIG. 1, and in particular to hot melt seal strip 38,typically the strip 38 is continuous and terminates, underneath region51 of overmold 36, at a location spaced at least 4 mm from face 16, FIG.4. Typically an extension of 6-12 mm of strip 38 will be positionedunderneath overmold 36. The termination of strip 38 at least 4 mm fromsurface 16 ensures that over a distance of at least 4 mm, the sealmaterial of overmold 36 is sealed directly to the media pack 2 adjacentend face 16. This will help avoid leak between the overmold 36 and themedia pack 2 at this location.

Referring to FIG. 4, molded seal component or overmold 36 furtherincludes air cleaner seal portion 54. Air cleaner seal portion 54includes a radial outer surface 56, configured in a preferred manner,for sealing with an air cleaner component. The particular surface 56 isdepicted, as a stepped surface portion 56 a having a shape similar tothe shape of the seal surface portion at reference 250 depicted in U.S.Pat. No. 6,350,291 at FIG. 7, the complete disclosure of which isincorporated herein by reference.

From review of FIG. 3, it can be seen that portion 40 of preform part 35is positioned to back up housing seal 56 and stepped portion 56 a ofmolded seal arrangement 36. Thus, preform part 35, in part, serves afunction of providing for rigid backup to the strength of the seal whenair cleaner seal portion 54 is compressed in the thickness (typically atleast 10% in thickness at the portion of most compression) uponinstallation in an air cleaner, with compression being of surface 56toward portion 40. Typically, the distance of compression is within therange of 1.5-2.8 mm, at the thickest part 56 b of seal 56, usually about1.9-2.5 mm.

The recess of surface 40 across face 16, from outer periphery 2 a of themedia pack 2, provides that the filter element 1 can be installed in aircleaners that are originally configured, for example, to receiveelements such as element 450, FIG. 15 of U.S. Pat. No. 6,350,291,incorporated herein by reference. Of course alternate configurations arepossible.

Media engagement portion 41 is configured to extend radially outwardly,in extension between portion 40 and edge 57. Media engagement portion 41is configured as a radially outwardly directed skirt, from region 40.This outward extension means that ends of outlet flutes in the z-filtermedia pack 2, at region 60, FIG. 3, are not closed to passage of airtherefrom, during filtering operation. If region 41 was not positionedas a flared, diagonal, skirt, but rather section 40 extended to point61, flutes in region 60 would be blocked by extension 41, for air flowtherefrom. This would lead to increased restriction, and less efficientuse of the media. Typically angle X, FIG. 6, is within the range of20°-70°, to accommodate the desired skirt. The angle X is the anglebetween the inside surface of skirt 41 and the media face 16.

Referring to FIG. 4, it is noted that for the particular arrangementshown skirt 41 is sized and positioned to leave region 64 in face 16(corresponding to the otherwise open ends of exit flutes in an outerflute wrap 46 a in the media pack 2), exposed to receive a portion ofmolded seal component 36 therein, as indicated at 66. This can providefor advantage. In particular, this allows some of overmold 36 to riseinto the media pack 2, as described below, during molding.

It is noted that for the preferred element 1 depicted in FIG. 4, noportion of the molded seal component 36 is positioned along interiorsurface 40 a of section 40. Further, typically no portion of molded sealcomponent 36 is provided along inner surface 41 a of region 41, exceptpossibly for some bleed or flash immediately adjacent edge 45. Thislatter, when deliverable, prevents undesired levels of flash acrosssurface 16.

Still referring to FIG. 4, media face cross piece arrangement 43 extendsacross media face 16, in engagement with region 41 of preformed part 35.Media face cross piece arrangement 43 prevents the media pack 2 fromtelescoping, in the direction of arrow 10, FIG. 1, during use.

A variety of cross piece configurations are useable. In FIG. 2, theparticular cross piece arrangement 43 depicted, comprises: a grid ofparallel extensions 43 a between opposite sides 22, 23; interconnectedby diagonal framework 43 b.

In FIG. 5, a perspective view is provided, showing preformed part 35. Itcan be seen that the preform part 35 can be formed as a single integralunit, for example through injection molding or other molding processes.It was typically formed from a polymer such as a (33% for example) glassfilled nylon material.

Referring again to FIG. 4, molded overmold or seal component 36 includesa portion 70 overlapping part of end 71 of preform part 35. This is anartifact from a preferred molding operation, as described below.

Referring to FIG. 4, it is noted that where cross-brace 43 engages skirt41, the angle of the skirt 41 relative to the face 16 may be interruptedsomewhat. However, in general, at other locations the skirt 41 willtypically have the preferred angle X as characterized above.

The techniques described in US Publication 2005/0166561 and PCT WO05/63361 could be applied in a wide variety of element configurationsand sizes. The following dimensions were provided in examples only, andto help understand the wide application of the described techniques. Theovermold 36, in its thickest location, could be about 10-12 mm thick,for example about 11.5 mm. The longest cross-sectional dimension of theracetrack shaped media pack could be about 300-320 mm, for example about308 mm. The shortest cross-sectional dimension of the racetrack shapedelement could about 115-125 mm, for example about 121 mm. The length ofthe straight sides could be about 175-195 mm, for example about 188 mm.

Before formation of arrangements such as described above is discussedapplication of the same principles in an alternate configuration will bediscussed in connection with FIGS. 7-10.

B. The Arrangement of FIGS. 7-10

Attention is first directed to FIG. 7. FIG. 7 is a side elevational viewof a filter element or cartridge 101. The filter element or cartridge101 comprises a z-filter media pack 102 and seal arrangement 103. Theelement 101 further includes optional end piece 104 at an end 102 b ofmedia pack 102 opposite from an end 102 a in which seal arrangement 103is located.

The media pack 102 comprises a coiled single facer having first andsecond, opposite, flow faces 105, 105 a. It would, of course, have anoutside tail end, not shown, which would be secured down, for example,with a sealant strip analogous to strip 38 above.

In general, and referring to FIG. 7, surface 106 of seal arrangement103, is configured to provide a housing seal, as an outwardly directedradial seal, with a housing or air cleaner component in use (of coursealternatives are possible). Surface 106 may be configured, incross-section, analogously to surface 56, FIG. 4.

Attention is now directed to FIG. 8, in which element 101 is depicted intop plan view. From the view of FIG. 7, it can be seen that element 101has a generally circular outer perimeter 108 defined by both the outercircumference of the seal arrangement 103 and media pack 102. In FIG. 8,grid work 109 is viewable, extending across flow face 105; in thisinstance face 105 preferably being an outlet flow face.

Attention is now directed to FIG. 9, which shows a cross-sectional viewthrough element 101. From FIG. 9, it can be seen that the sealarrangement 103 comprises a preformed part 110 and an overmold or moldedseal component 111. The preform part 110 and molded seal component 111may generally be analogous to the preform part 35 and molded sealcomponent 36 of the embodiment shown in FIGS. 1-5, except made with around outer perimeter.

Specifically, element 101 includes a core 113, around which the mediapack 102 is wound. Core 113 can be provided in snap fit engagement witha portion 114 of preform part 110. A variety of engagement arrangementscan be used, including the one, for example, described at FIG. 5 in U.S.Pat. No. 6,517,598, incorporated herein by reference. Core 113 is shownin schematic. It would typically be provided with a plug therein. Theplug could be integral with a remainder of core 113 or is added thereto.

In FIG. 10, an enlarged fragmentary view of a portion of FIG. 9 isshown. The preform part 110 includes a housing seal support 116; and, amedia pack engagement portion 117, configured as a radially outwardlydirected skirt 118; and media face cross piece arrangement 109 (FIG. 8).(At region 114 the inside outward skirt 118 is shown filled because thecross-section is taken through cross piece grid work 109, FIG. 8.) Forelement 101, these components generally provide the same basic operationas the analogous components for element 1, FIG. 1.

C. Process for Assembly of Elements (Air Filter Cartridges) According toFIGS. 1-10

In general, elements (air filter cartridges) corresponding to element orcartridge 1, FIG. 1, and element or cartridge 101, FIG. 6, are formedthe processes involving the following:

-   -   1. Preforming the media pack component (2, 102);    -   2. Preforming the preformed part (35, 110) of the seal        arrangement;    -   3. Positioning the preform part (35, 110) and media pack        component (2, 102) appropriately with respect to one another in        a mold.    -   4. Molding (in the examples shown by overmolding) seal material        to form the appropriate molded seal component of the        arrangement.    -   5. Demolding.    -   6. Optionally placing the skid (30, 104) on an end of the        element opposite the seal.

In this context, the term “overmolding” and variants thereof are meantto refer to molding a molded seal component 36, 111 in position: (a)with a portion of the molded seal component 36 over the outside of jointbetween the preformed part (35, 110) of the seal arrangement and themedia pack (2, 102); and, (b) with a portion of the same seal component36, 111 (i.e. preferably a portion integral with a remainder of theovermold) positioned to form an air cleaner seal. Typical and preferredprocesses will use, for the formation of the molded seal component, afoaming polyurethane, as described below. Herein, a molded sealcomponent 36 which has been made by overmolding as defined, willsometimes be referred to as an overmold. The portions of the overmoldseal, are preferably integral with one another; the overmold 36, 111being preferably molded from a single pool of polymer.

Typically, the thickness of the molded seal component, in the region ofthe seal surface, is configured so that compression of the thickness ofthe thickest portion of the molded seal component in this region, willbe at least 10%, and typically at least 15%, when the element (1, 101)is installed in an air cleaner for use. This can be accomplished withconfigurations as shown, using materials as described below.

A typical process is described herein, in connection with FIGS. 11-16.

Attention is first directed to FIG. 11. In FIG. 11, reference numeral180 identifies a mold arrangement useable to form the overmold sealarrangement of FIGS. 1-10. Mold arrangement 180 is shown in fragmentary,cross-section. The portions indicated will provide an understanding ofhow the overmold seal arrangement can be formed. The remainder of themold will be configured either round or obround, etc., depending on theparticular instance of application.

Referring to FIG. 11, the particular mold arrangement 180 depicted is amulti-part mold 181. That is, the mold 180 includes more than one piecefit together, to form the mold in which the overmolding process occurs.The particular multi-part mold 180 depicted comprises three parts 183,184 and 185 that are fit together, to form the mold. Aperture 189, whichextends through three parts 183, 184, 185 when they are appropriatelyaligned, FIG. 11, can be used to receive a pin or similar member tosecure the mold together.

In general, part 183 forms the basic mold structure including: an innerreservoir portion 192, in which uncured resin is placed, for the moldingprocess; inner wall 193, against which a preformed part would be placedin use; shelf 194 on which an edge of the preform part would rest,during the molding process; central wall 195 and shelf 196 whichsupports additional mold parts as described; and, outer wall 197, whichprovides an outer support structure to the assembly 180.

The second part 184 comprises a mold insert having an extension 200 witha surface 201 that forms a portion of the outer surface of the moldedpart of the seal arrangement in use. In this instance surface 201includes a portion 202 which, in combination with central wall 195provides a mold undercut 203 molding a particular portion of the sealingsurface of the resulting seal portion, as discussed below in connectionwith FIG. 15. Part 184 further includes upper extension 205 which restson shoulder 196.

Finally, part 185 includes inner wall 215 and upper flange 218. Theflange 218 extends over portion 205 of center part 184. Inner wall 215includes a surface 216 which will define selected portions of the sealmember, during the molding process, as discussed below in connectionwith FIG. 15. Section 217 will cap the mold, and engage media, during amolding operation as described.

Attention is now directed to FIG. 12, in which assembly 180 is depictedwith curable material 225 positioned within reservoir 192 up to fillline 226. The material 225 would generally comprise resin which, duringa cure process, will foam and rise as a cure to form the moldable sealcomponent. Typically, during molding and use the material 225 willexpand in volume at least 80%, a preferred material increasing about100%, in volume.

In FIG. 13, the mold assembly 180 having resin 225 therein is shownhaving preformed part 230 therein. The preform part 230 couldcorrespond, for example, to preform part 35, FIG. 1. It could alsocorrespond to preform part 110, FIG. 7. However if used with thearrangement of FIG. 7, in some instances it would already be attached tothe media pack.

Attention is now directed to FIG. 14 in which the mold arrangement 180is depicted with preform part 230 and media pack 231 positionedappropriately. It is noted that an outer surface 232 of media pack 231is sized to engage portion 217 of the mold part 185.

Attention is now directed to FIG. 15. In FIG. 15 the material at 235 ismeant to indicate the foamed, risen, substantially cured resin; i.e.,the overmold (corresponding to overmold 36, FIG. 1, or overmold 103,FIG. 7). By the term “substantially cured” it is meant that the resin iscured sufficiently to have reached a shape which will generally bemaintained, as it further cures. From FIG. 15, some of the followingimportant features relating to the molding operation can be understood:

-   -   1. At region 240, the most outwardly projecting portion of the        molded seal member 235 (number that above) is formed. Portion        240 then, will form the outer most portion of the outwardly        directed radial seal member, i.e., the part that compresses most        in use as an air cleaner seal;    -   2. Surface 241 is a portion of mold undercut, which is used to        form a portion of region 240.    -   3. At region 245, rise of the material 235 around the outside        surface 232 of the media pack 231 is capped or stopped by mold        piece 185, in particular by region 216 of mold piece 185.

At location 247, some of the resin of overmold 235 has risen into themedia pack between an outer most layer 248 of the media pack 231 and thelayer underneath. This rise will tend to close off any otherwise openflutes at this location. In general, this will render the outer mostlayer of the media pack (for example layer 46 a, FIG. 4) such that whileit can be used for filtering material, air must pass into the next innerlayer, before it can exit the media pack. What this means or ensures isthat even if the outer most wrap of media pack is damaged duringhandling or installation, leakage will not result. Thus, in a typicalarrangement made in this manner, a third set of flutes, closed at bothends, is present in the media pack. This third set is present,preferably, only in the outermost wrap. These flutes would otherwise beoutlet flutes, and will sometimes be referred to by such terms.

For the process shown in FIGS. 11-16, the media pack is one which hasclosed ends at the inlet flutes, adjacent the outlet flow face, dartedclosed, to provide the edges viewable. Alternates of course arepossible, including ones that are not darted at all. The overmoldmaterial is shown risen up into the open ends of the outlet flutes, atthe outlet face of the media, in the region indicated at 247.

Along regions 249, 250, the resin material 236 completely lines an outersurface of preform 230, securing it in place. At region 255, material235 is positioned over a part of an end 256 of preform 230.

In the particular arrangement shown, FIG. 15, the overmold 235 is asingle integral member, molded from the resin 225, FIG. 14.

Demolding can be accomplished by forcing the element out of the mold180, in a powered process. Equipment to cause the forcing can engage thecross-pieces on the preform 230. Generally the overmold 235 willcompress sufficiently, to be pushed past undercuts in the mold. It isanticipated that typically, with materials and configurations describedherein, demolding can be accomplished with a force of 110 lbs. or less,typically about 100 lbs. (The demolding force would typically be applieddirectly to the gridwork of the preform 35, 110.)

The optional preform skid skirt at the opposite end of the element, canbe applied either before or after molding. In general, if a center plugis used within the media, it would be preformed before the describedmolding process. However, in some instances a center plug can be moldedat the same time as the overmold. This latter would require ensuringthat a part of the mold or some other configuration is provided, forappropriate dispensing of the urethane to accomplish this.

It is noted that in some instances, as described above, the preform 230could be attached to the media pack 231 by snap-fit arrangement.

In FIG. 16, the mold 180 is depicted with the media pack 231 and preform230 positioned therein, at molding. In this instance the media pack 231is depicted without the option skid skirt mounted therein.

D. The Optional Skid Skirt

In the discussion above with respect to FIG. 1, it was indicated thatthe skid skirt 30 was an optional component. This component is depictedin FIGS. 17 and 18.

Referring first to FIG. 17, a top plan view, the skid skirt 30 isdepicted. In FIG. 18, the skid skirt 30 is depicted in cross-sectionalview. Referring to FIG. 18, receiving area 30 a for the media pack, canbe viewed, along with outside surface 30 b configured to engagecomponentry in a housing, during installation, as desired. From theprinciples described in FIGS. 17 and 18, an analogous, but circular,component can be understood, if desired, for application in a circulararrangement. The skid skirt 30 is typically formed from a glass filled(for example 33% glass filled) nylon, secured in position with anadhesive.

E. The Curable Seal Resin

Typically with such arrangements, the polyurethane formulation chosenprovides for a high foam, very soft, molded end cap. In general, theprincipal issue is to utilize a formulation that provides for an end capthat is such that a robust seal will result under conditions which willallow for hand assembly and disassembly. This generally means that theseal range which has material is a relatively low density, and exhibitsappropriate and desirable compression load deflection and compressionset.

Typically the formula chosen will be such as to provide end caps havingan as molded density of no greater than 28 lbs./cubic foot, usually nomore than 22 lbs./cubic foot, often no greater than 18 lbs/cubic feetand preferably within the range of 12 to 17 lbs/cubic foot.

Herein the term “as molded density” is meant to refer to its normaldefinition of weight divided by volume. A water displacement test orsimilar test can be utilized to determine volume of a sample of themolded foam. It is not necessary when applying the volume test, topursue water absorption into the pores of the porous material, and todisplace the air the pores represent. Thus, the water volumedisplacement test used, to determine sample volume, would be animmediate displacement, without waiting for a long period to displaceair within the material pores. Alternately stated, only the volumerepresented by the outer perimeter of the sample need be used for the asmolded density calculation.

In general, compression load deflection is a physical characteristicthat indicates firmness, i.e. resistance to compression. In general, itis measured in terms of the amount of pressure required to deflect agiven sample of 25% of its thickness. Compression load deflection testscan be conducted in accord with ASTM 3574, incorporated herein byreference. In general, compression load deflection may be evaluated inconnection with aged samples. A typical technique is to measure thecompression load deflection on samples that have been fully cured for 72hours at 75° F. or forced cured at 190° F. for 5 hours.

Preferred materials will be ones which when molded, show a compressionload deflection, in accord with ASTM 3574, on a sample measured afterheat aging at 158° F. for seven days, on average, of 14 psi or less,typically within the range of 6-14 psi, and preferably within the rangeof 7-10 psi.

Compression set is an evaluation of the extent to which a sample of thematerial (that is subjected to compression of the defined type and underdefined conditions), returns to its previous thickness or height whenthe compression forces are removed. Conditions for evaluatingcompression set on urethane materials are also provided in ASTM 3574.

Typical desirable materials will be ones which, upon cure, provide amaterial that has a compression set of no more than about 18%, andtypically about 8-13%, when measured on a sample compressed to 50% ofits height and held at that compression at a temperature of 180° F. for22 hours.

In general, the compression load deflection and compression setcharacteristics can be measured on sample plugs prepared from the sameresin as used to form the end cap, or on sample cut from the end cap.Typically, industrial processing methods will involve regularly makingtest sample plugs made from the resin material, rather than directtesting on portions cut from molded end caps.

Urethane resin systems useable to provide materials having physicalproperties within the as molded density, compression set and compressionload deflection definition as provided above, can be readily obtainedfrom a variety of polyurethane resin formulators, including suchsuppliers as BASF Corp., Wyandotte Mich., 48192.

In general, with any given industrial process to select the appropriatephysical characteristics with respect to the material, the key issuewill be management of the desired characteristics and the final product,with respect to mounting and dismounting of the element, as well asmaintenance of the seal over a variety of conditions. The physicalcharacteristics provided above are useable, but are not specificallylimiting with respect to products that may be considered viable. Inaddition, various element manufacturers, depending on the circumstances,may desire still further specifications, for example, cold temperaturecompression deflection, typically measured on the sample cooled to −40°F., with the specification being for the pressure required to cause thecompression under the ASTM test, for example, being 100 psi max.

One example usable material includes the following polyurethane,processed to an end product having an “as molded” density of 14-22pounds per cubic foot. The polyurethane comprises a material made withI36070R resin and I305OU isocyanate, which are sold exclusively to theassignee Donaldson by BASF Corporation, Wyandotte, Mich. 48192.

The materials would typically be mixed in a mix ratio of 100 partsI36070R resin to 45.5 parts I3050U isocyanate (by weight). The specificgravity of the resin is 1.04 (8.7 lbs/gallon) and for the isocyanate itis 1.20 (10 lbs/gallon). The materials are typically mixed with a highdynamic shear mixer. The component temperatures should be 70-95° F. Themold temperatures should be 115-135° F.

The resin material I36070R has the following description:

(a) Average Molecular Weight

-   -   1) Base polyether polyol=500-15,000    -   2) Diols=0-10,000    -   3) Triols=500-15,000

(b) Average Functionality

-   -   1) total system=1.5-3.2

(c) Hydroxyl Number

-   -   1) total systems=100-300

(d) Catalysts

-   -   1) amine=Air Products 0.1-3.0 PPH

(e) Surfactants

-   -   1) total system=0.1-2.0 PPH

(f) Water

-   -   1) total system=0.2-0.5%

(g) Pigments/Dyes

-   -   1) total system=1-5% carbon black

(h) Blowing Agent

-   -   1) water.

The I3050U isocyanate description is as follows:

(a) NCO content—22.4-23.4 wt %

(b) Viscosity, cps at 25° C.=600-800

(c) Density=1.21 g/cm³ at 25° C.

(d) Initial boiling pt.—190° C. at 5 mm Hg

(e) Vapor pressure=0.0002 Hg at 25° C.

(f) Appearance—colorless liquid

(g) Flash point (Densky-Martins closed cup)=200° C.

F. Z-Filter Media Generally

Herein above it was discussed in general the media packs usable in thearrangements described, for example as media packs 2, 102, comprisez-filter media packs. It was indicated that a variety of alternate fluteshapes and seal types can be used in such media packs.

1. Z-Filter Media Configurations, Generally

Fluted filter media can be used to provide fluid filter constructions ina variety of manners. One well known manner is as a z-filterconstruction. The term “z-filter construction” as used herein, is meantto refer to a filter construction in which individual ones ofcorrugated, folded or otherwise formed filter flutes are used to definesets of longitudinal, typically parallel, inlet and outlet filter flutesfor fluid flow through the media; the fluid flowing along the length ofthe flutes between opposite inlet and outlet flow ends (or flow faces)of the media. Some examples of z-filter media are provided in U.S. Pat.Nos. 5,820,646; 5,772,883; 5,902,364; 5,792,247; 5,895,574; 6,210,469;6,190,432; 6,350,296; 6,179,890; 6,235,195; Des. 399,944; Des. 428,128;Des. 396,098; Des. 398,046; and, Des. 437,401; each of these fifteencited references being incorporated herein by reference.

One type of z-filter media, utilizes two specific media componentsjoined together, to form the media construction. The two components are:(1) a fluted (typically corrugated) media sheet; and, (2) a facing mediasheet. The facing media sheet is typically non-corrugated, however itcan be corrugated, for example perpendicularly to the flute direction asdescribed in U.S. provisional 60/543,804, filed Feb. 11, 2004,incorporated herein by reference.

The fluted (typically corrugated) media sheet and the facing media sheettogether, are used to define media having parallel inlet and outletflutes. In some instances, the fluted sheet and facing sheet are securedtogether and are then coiled to form a z-filter media construction. Sucharrangements are described, for example, in U.S. Pat. Nos. 6,235,195 and6,179,890, each of which is incorporated herein by reference. In certainother arrangements, some non-coiled sections of fluted media secured tofacing media, are stacked on one another, to create a filterconstruction. An example of this is described in FIG. 11 of 5,820,646,incorporated herein by reference.

For specific applications as described herein, coiled arrangements arepreferred. Typically, coiling of the fluted sheet/facing sheetcombination around itself, to create a coiled media pack, is conductedwith the facing sheet directed outwardly. Some techniques for coilingare described in U.S. provisional application 60/467,521, filed May 2,2003 and PCT Application US 04/07927, filed Mar. 17, 2004, each of whichis incorporated herein by reference. The resulting coiled arrangementgenerally has, as the outer surface of the media pack, a portion of thefacing sheet.

The term “corrugated” used herein to refer to structure in media, ismeant to refer to a flute structure resulting from passing the mediabetween two corrugation rollers, i.e., into a nip or bite between tworollers, each of which has surface features appropriate to cause acorrugation affect in the resulting media. The term “corrugation” is notmeant to refer to flutes that are formed by techniques not involvingpassage of media into a bite between corrugation rollers. However, theterm “corrugated” is meant to apply even if the media is furthermodified or deformed after corrugation, for example by the foldingtechniques described in PCT WO 04/007054, published Jan. 22, 2004,incorporated herein by reference.

Corrugated media is a specific form of fluted media. Fluted media ismedia which has individual flutes (for example formed by such techniquesas corrugating or folding) extending thereacross.

Serviceable filter element or filter cartridge configurations utilizingz-filter media are sometimes referred to as “straight through flowconfigurations” or by variants thereof. In general, in this context whatis meant is that the serviceable filter elements generally have an inletflow end (or face) and an opposite exit flow end (or face), with flowentering and exiting the filter cartridge in generally the same straightthrough direction. The term “serviceable” in this context is meant torefer to a media containing filter cartridge that is periodicallyremoved and replaced from a corresponding fluid cleaner. In someinstances, each of the inlet flow end and outlet flow end will begenerally flat or planar, with the two parallel to one another. However,variations from this, for example non-planar faces are possible.

A straight through flow configuration (especially for a coiled mediapack) is, for example, in contrast to serviceable filter cartridges suchas cylindrical pleated filter cartridges of the type shown in U.S. Pat.No. 6,039,778, incorporated herein by reference, in which the flowgenerally makes a turn as its passes through the serviceable cartridge.That is, in a 6,039,778 filter, the flow enters the cylindrical filtercartridge through a cylindrical side, and then turns to exit through anend face (in forward-flow systems). In a typical reverse-flow system,the flow enters the serviceable cylindrical cartridge through an endface and then turns to exit through a side of the cylindrical filtercartridge. An example of such a reverse-flow system is shown in U.S.Pat. No. 5,613,992, incorporated by reference herein.

The term “z-filter media construction” and variants thereof as usedherein, without more, is meant to refer to any or all of: a web ofcorrugated or otherwise fluted media secured to facing media withappropriate sealing to allow for definition of inlet and outlet flutes;or, such a media coiled or otherwise constructed or formed into a threedimensional network of inlet and outlet flutes; and/or, a filterconstruction including such media.

In FIG. 19, an example of media 401 useable in z-filter media is shown.The media 401 is formed from a corrugated (fluted) sheet 403 and afacing sheet 404.

In general, the corrugated sheet 403, FIG. 19, is of a type generallycharacterized herein as having a regular, curved, wave pattern of flutesor corrugations 407. The term “wave pattern” in this context, is meantto refer to a flute or corrugated pattern of alternating troughs 407 band ridges 407 a. The term “regular” in this context is meant to referto the fact that the pairs of troughs and ridges (407 b, 407 a)alternate with generally the same repeating corrugation (or flute) shapeand size. (Also, typically in a regular configuration each trough 407 bis substantially an inverse of each ridge 407 a.) The term “regular” isthus meant to indicate that the corrugation (or flute) pattern comprisestroughs and ridges with each pair (comprising an adjacent trough andridge) repeating, without substantial modification in size and shape ofthe corrugations along at least 70% of the length of the flutes. Theterm “substantial” in this context, refers to a modification resultingfrom a change in the process or form used to create the corrugated orfluted sheet, as opposed to minor variations from the fact that themedia sheet 403 is flexible. With respect to the characterization of arepeating pattern, it is not meant that in any given filterconstruction, an equal number of ridges and troughs is necessarilypresent. The media 401 could be terminated, for example, between a paircomprising a ridge and a trough, or partially along a pair comprising aridge and a trough. (For example, in FIG. 19 the media 401 depicted infragmentary has eight complete ridges 407 a and seven complete troughs407 b.) Also, the opposite flute ends (ends of the troughs and ridges)may vary from one another. Such variations in ends are disregarded inthese definitions, unless specifically stated. That is, variations inthe ends of flutes are intended to be covered by the above definitions.

In the context of the characterization of a “curved” wave pattern ofcorrugations, the term “curved” is meant to refer to a corrugationpattern that is not the result of a folded or creased shape provided tothe media, but rather the apex 407 a of each ridge and the bottom 407 bof each trough is formed along a radiused curve. Although alternativesare possible, a typical radius for such z-filter media would be at least0.25 mm and typically would be not more than 3 mm. (Media that is notcurved, by the above definition, can also be useable.)

An additional characteristic of the particular regular, curved, wavepattern depicted in FIG. 19, for the corrugated sheet 403, is that atapproximately a midpoint 430 between each trough and each adjacentridge, along most of the length of the flutes 407, is located atransition region where the curvature inverts. For example, viewing backside or face 403 a, FIG. 19, trough 407 b is a concave region, and ridge407 a is a convex region. Of course when viewed toward front side orface 403 b, trough 407 b of side 403 a forms a ridge; and, ridge 407 aof face 403 a, forms a trough. (In some instances, region 430 can be astraight segment, instead of a point, with curvature inverting at endsof the straight segment 430.)

A characteristic of the particular regular, curved, wave patterncorrugated sheet 403 shown in FIG. 19, is that the individualcorrugations are generally straight. By “straight” in this context, itis meant that through at least 70% (typically at least 80%) of thelength between edges 408 and 409, the ridges 407 a and troughs 407 b donot change substantially in cross-section. The term “straight” inreference to corrugation pattern shown in FIG. 19, in part distinguishesthe pattern from the tapered flutes of corrugated media described inFIG. 1 of WO 97/40918 and PCT Publication WO 03/47722, published Jun.12, 2003, incorporated herein by reference. The tapered flutes of FIG. 1of WO 97/40918, for example, would be a curved wave pattern, but not a“regular” pattern, or a pattern of straight flutes, as the terms areused herein.

Referring to the present FIG. 19 and as referenced above, the media 401has first and second opposite edges 408 and 409. When the media 401 iscoiled and formed into a media pack, in general edge 409 will form aninlet end for the media pack and edge 408 an outlet end, although anopposite orientation is possible as discussed below with respect to FIG.24.

Adjacent edge 408 the sheets 403, 404 are sealed to one another, forexample by sealant, in this instance in the form of a sealant bead 410,sealing the corrugated (fluted) sheet 403 and the facing sheet 404together. Bead 410 will sometimes be referred to as a “single facer”bead, when it is applied as a bead between the corrugated sheet 403 andfacing sheet 404, to form the single facer or media strip 401. Sealantbead 410 seals closed individual flutes 411 adjacent edge 408, topassage of air therefrom.

Adjacent edge 409, is provided sealant, in this instance in the form ofa seal bead 414. Seal bead 414 generally closes flutes 415 to passage ofunfiltered fluid therein, adjacent edge 409. Bead 414 would typically beapplied as the media 401 is coiled about itself, with the corrugatedsheet 403 directed to the inside. Thus, bead 414 will form a sealbetween a back side 417 of facing sheet 404, and side 418 of thecorrugated sheet 403. The bead 414 will sometimes be referred to as a“winding bead” when it is applied as the strip 401 is coiled into acoiled media pack. If the media 401 were cut in strips and stacked,instead of coiled, bead 414 would be a “stacking bead.”

In some applications, the corrugated sheet 403 is also tacked to thefacing sheet 4 at various points along the flute length, as shown atlines 404 a.

Referring to FIG. 19, once the media 401 is incorporated into a mediapack, for example by coiling or stacking, it can be operated as follows.First, air in the direction of arrows 412, would enter open flutes 411adjacent end 409. Due to the closure at end 408, by bead 410, the airwould pass through the media shown by arrows 413. It could then exit themedia pack, by passage through open ends 415 a of the flutes 415,adjacent end 408 of the media pack. Of course operation could beconducted with air flow in the opposite direction, as discussed forexample with respect to FIG. 24. The point being that in typical airfilter applications, at one end or face of the media pack unfiltered airflow goes in, and at an opposite end or face the filtered air flow goesout, with no unfiltered air flow through the pack or between the faces.

For the particular arrangement shown herein in FIG. 19, the parallelcorrugations 7 a, 7 b are generally straight completely across themedia, from edge 708 to edge 709. Straight flutes or corrugations can bedeformed or folded at selected locations, especially at ends.Modifications at flute ends for closure are generally disregarded in theabove definitions of “regular,” “curved” and “wave pattern.”

Z-filter constructions which do not utilize straight, regular curvedwave pattern corrugation (flute) shapes are known. For example in Yamadaet al. U.S. Pat. No. 5,562,825 corrugation patterns which utilizesomewhat semicircular (in cross section) inlet flutes adjacent narrowV-shaped (with curved sides) exit flutes are shown (see FIGS. 1 and 3,of 5,562,825). In Matsumoto, et al. U.S. Pat. No. 5,049,326 circular (incross-section) or tubular flutes defined by one sheet having half tubesattached to another sheet having half tubes, with flat regions betweenthe resulting parallel, straight, flutes are shown, see FIG. 2 ofMatsumoto '326. In Ishii, et al. U.S. Pat. No. 4,925,561 (FIG. 1) flutesfolded to have a rectangular cross section are shown, in which theflutes taper along their lengths. In WO 97/40918 (FIG. 1), flutes orparallel corrugations which have a curved, wave patterns (from adjacentcurved convex and concave troughs) but which taper along their lengths(and thus are not straight) are shown. Also, in WO 97/40918 flutes whichhave curved wave patterns, but with different sized ridges and troughs,are shown.

In general, the filter media is a relatively flexible material,typically a non-woven fibrous material (of cellulose fibers, syntheticfibers or both) often including a resin therein, sometimes treated withadditional materials. Thus, it can be conformed or configured into thevarious corrugated patterns, without unacceptable media damage. Also, itcan be readily coiled or otherwise configured for use, again withoutunacceptable media damage. Of course, it must be of a nature such thatit will maintain the required corrugated configuration, during use.

In the corrugation process, an inelastic deformation is caused to themedia. This prevents the media from returning to its original shape.However, once the tension is released the flute or corrugations willtend to spring back, recovering only a portion of the stretch andbending that has occurred. The facing sheet is sometimes tacked to thefluted sheet, to inhibit this spring back in the corrugated sheet.

Also, typically, the media contains a resin. During the corrugationprocess, the media can be heated to above the glass transition point ofthe resin. When the resin then cools, it will help to maintain thefluted shapes.

The media of the corrugated sheet 403, facing sheet 404 or both, can beprovided with a fine fiber material on one or both sides thereof, forexample in accord with U.S. Pat. No. 6,673,136, incorporated herein byreference.

An issue with respect to z-filter constructions relates to closing ofthe individual flute ends. Typically a sealant or adhesive is provided,to accomplish the closure. As is apparent from the discussion above, intypical z-filter media, especially that which uses straight flutes asopposed to tapered flutes, large sealant surface areas (and volume) atboth the upstream end and the downstream end are needed. High qualityseals at these locations are critical to proper operation of the mediastructure that results. The high sealant volume and area, creates issueswith respect to this.

Attention is now directed to FIG. 20, in which a z-filter mediaconstruction 440 utilizing a regular, curved, wave pattern corrugatedsheet 443, and a facing (in this instance non-corrugated) sheet 444, isdepicted. The distance D1, between points 450 and 451, defines theextension of facing media 444 in region 452 underneath a givencorrugated flute 453. The length D2 of the arcuate media for thecorrugated flute 453, over the same distance D1 is of course larger thanD1, due to the shape of the corrugated flute 453. For a typical regularshaped media used in fluted filter applications, the linear length D2 ofthe media 453 between points 450 and 451 will generally be at least 1.2times D1. Typically, D2 would be within a range of 1.2-2.0 time D1,inclusive. One particularly convenient arrangement for air filters has aconfiguration in which D2 is about 1.25-1.35×D1. Such media has, forexample, been used commercially in Donaldson Powercore™ Z-filterarrangements. Herein the ratio D2/D1 will sometimes be characterized asthe flute/flat ratio or media draw for the corrugated (fluted) media.

In the corrugated cardboard industry, various standard flutes have beendefined. For example the standard E flute, standard X flute, standard Bflute, standard C flute and standard A flute. FIG. 21, attached, incombination with Table A below provides definitions of these flutes.

Donaldson Company, Inc., (DCI) the assignee of the present disclosure,has used variations of the standard A and standard B flutes, in avariety of z-filter arrangements. These flutes are also defined in TableA and FIG. 21.

TABLE A (Flute definitions for FIG. 3) DCI A Flute: Flute/flat = 1.52:1;The Radii (R) are as follows: R1000 = .0675 inch (1.715 mm); R1001 =.0581 inch (1.476 mm); R1002 = .0575 inch (1.461 mm); R1003 = .0681 inch(1.730 mm); DCI B Flute: Flute/flat = 1.32:1; The Radii (R) are asfollows: R1004 = .0600 inch (1.524 mm); R1005 = .0520 inch (1.321 mm);R1006 = .0500 inch (1.270 mm); R1007 = .0620 inch (1.575 mm); Std. EFlute: Flute/flat = 1.24:1; The Radii (R) are as follows: R1008 = .0200inch (.508 mm); R1009 = .0300 inch (.762 mm); R1010 = .0100 inch (.254mm); R1011 = .0400 inch (1.016 mm); Std. X Flute: Flute/flat = 1.29:1;The Radii (R) are as follows: R1012 = .0250 inch (.635 mm); R1013 =.0150 inch (.381 mm); Std. B Flute: Flute/flat = 1.29:1; The Radii (R)are as follows: R1014 = .0410 inch (1.041 mm); R1015 = .0310 inch (.7874mm); R1016 = .0310 inch (.7874 mm); Std. C Flute: Flute/flat = 1.46:1;The Radii (R) are as follows: R1017 = .0720 inch (1.829 mm); R1018 =.0620 inch (1.575 mm); Std. A Flute: Flute/flat = 1.53:1; The Radii (R)are as follows: R1019 = .0720 inch (1.829 mm); R1020 = .0620 inch (1.575mm).

Of course other, standard, flutes definitions from the corrugated boxindustry are known.

In general, standard flute configurations from the corrugated boxindustry can be used to define corrugation shapes or approximatecorrugation shapes for corrugated media. Comparisons above between theDCI A flute and DCI B flute, and the corrugation industry standard A andstandard B flutes, indicate some convenient variations. A variety ofother flute sizes and shapes can also be used with arrangementsdescribed herein.

2. Manufacture of Coiled Media Configurations Using Fluted Media,Generally

In FIG. 22, one example of a manufacturing process for making a mediastrip corresponding to strip 401, FIG. 19 is shown. In general, facingsheet 464 and the fluted (corrugated) sheet 466 having flutes 468 arebrought together to form a media web 469, with an adhesive bead locatedtherebetween at 470. The adhesive bead 470 will form a single facer bead410, FIG. 19. An optional darting process occurs at station 471 to formcenter darted section 472 located mid-web. The z-filter media or Z-mediastrip 474 can be cut or slit at 475 along the bead 470 to create twopieces 476, 477 of z-filter media 474, each of which has an edge with astrip of sealant (single facer bead) extending between the corrugatingand facing sheet. Of course, if the optional darting process is used,the edge with a strip of sealant (single facer bead) would also have aset of flutes darted at this location.

Also, if tack beads or other tack connections 404 a, FIG. 19, are used,they can be made, as the sheets 464, 466 are brought together.

Techniques for conducting a process as characterized with respect toFIG. 22 are described in PCT WO 04/007054, published Jan. 22, 2004incorporated herein by reference.

Still in reference to FIG. 22, before the z-filter media 474 is putthrough the darting station 471 and eventually slit at 475, it must beformed. In the schematic shown in FIG. 22, this is done by passing asheet of media 492 through a pair of corrugation rollers 494, 495. Inthe schematic shown in FIG. 22, the sheet of media 492 is unrolled froma roll 496, wound around tension rollers 498, and then passed through anip or bite 502 between the corrugation rollers 494, 495. Thecorrugation rollers 494, 495 have teeth 504 that will give the generaldesired shape of the corrugations after the flat sheet 492 passesthrough the nip 502. After passing through the nip 502, the sheet 492becomes corrugated across the machine direction and is referenced at 466as the corrugated sheet. The corrugated sheet 466 is then secured tofacing sheet 464. (The corrugation process may involve heating themedia, in some instances.)

Still in reference to FIG. 22, the process also shows the facing sheet464 being routed to the darting process station 471. The facing sheet464 is depicted as being stored on a roll 506 and then directed to thecorrugated sheet 466 to form the Z-media 474. The corrugated sheet 466and the facing sheet 464 are secured together by adhesive or by othermeans (for example by sonic welding).

Referring to FIG. 22, an adhesive line 470 is shown used to securecorrugated sheet 466 and facing sheet 464 together, as the sealant bead.Alternatively, the sealant bead for forming the facing bead could beapplied as shown as 470 a. If the sealant is applied at 470 a, it may bedesirable to put a gap in the corrugation roller 495, and possibly inboth corrugation rollers 494, 495, to accommodate the bead 470 a.

The type of corrugation provided to the corrugated media is a matter ofchoice, and will be dictated by the corrugation or corrugation teeth ofthe corrugation rollers 494, 495. One preferred corrugation pattern willbe a regular curved wave pattern corrugation of straight flutes, asdefined herein above. A typical regular curved wave pattern used, wouldbe one in which the distance D2, as defined above, in a corrugatedpattern is at least 1.2 times the distance D1 as defined above. In onepreferred application, typically D2=1.25-1.35×D1. In some instances thetechniques may be applied with curved wave patterns that are not“regular,” including, for example, ones that do not use straight flutes.

As described, the process shown in FIG. 22 can be used to create thecenter darted section 472. FIG. 23 shows, in cross-section, one of theflutes 468 after darting and slitting.

A fold arrangement 518 can be seen to form a darted flute 520 with fourcreases 521 a, 521 b, 521 c, 521 d. The fold arrangement 518 includes aflat first layer or portion 522 that is secured to the facing sheet 464.A second layer or portion 524 is shown pressed against the first layeror portion 522. The second layer or portion 524 is preferably formedfrom folding opposite outer ends 526, 527 of the first layer or portion522.

Still referring to FIG. 23, two of the folds or creases 521 a, 521 bwill generally be referred to herein as “upper, inwardly directed” foldsor creases. The term “upper” in this context is meant to indicate thatthe creases lie on an upper portion of the entire fold 520, when thefold 520 is viewed in the orientation of FIG. 23. The term “inwardlydirected” is meant to refer to the fact that the fold line or creaseline of each crease 521 a, 521 b, is directed toward the other.

In FIG. 23, creases 521 c, 521 d, will generally be referred to hereinas “lower, outwardly directed” creases. The term “lower” in this contextrefers to the fact that the creases 521 c, 521 d are not located on thetop as are creases 521 a, 521 b, in the orientation of FIG. 23. The term“outwardly directed” is meant to indicate that the fold lines of thecreases 521 c, 521 d are directed away from one another.

The terms “upper” and “lower” as used in this context are meantspecifically to refer to the fold 520, when viewed from the orientationof FIG. 23. That is, they are not meant to be otherwise indicative ofdirection when the fold 520 is oriented in an actual product for use.

Based upon these characterizations and review of FIG. 23, it can be seenthat a preferred regular fold arrangement 518 according to FIG. 23 inthis disclosure is one which includes at least two “upper, inwardlydirected, creases.” These inwardly directed creases are unique and helpprovide an overall arrangement in which the folding does not cause asignificant encroachment on adjacent flutes.

A third layer or portion 528 can also be seen pressed against the secondlayer or portion 524. The third layer or portion 528 is formed byfolding from opposite inner ends 530, 531 of the third layer 528.

Another way of viewing the fold arrangement 518 is in reference to thegeometry of alternating ridges and troughs of the corrugated sheet 566.The first layer or portion 522 is formed from an inverted ridge. Thesecond layer or portion 524 corresponds to a double peak (afterinverting the ridge) that is folded toward, and in preferredarrangements folded against, the inverted ridge.

Techniques for providing the optional dart described in connection withFIG. 23, in a preferred manner, are described in PCT WO 04/007054,incorporated herein by reference. Techniques for coiling the media, withapplication of the winding bead, are described in PCT application US04/07927, filed Mar. 17, 2004 and incorporated herein by reference.

Techniques described herein are particularly well adapted for use withmedia packs that result from coiling a single sheet comprising acorrugated sheet/facing sheet combination, i.e., a “single facer” strip.Certain of the techniques can be applied with arrangements that, insteadof being formed by coiling, are formed from a plurality of strips ofsingle facer.

Coiled media pack arrangements can be provided with a variety ofperipheral perimeter definitions. In this context the term “peripheral,perimeter definition” and variants thereof, is meant to refer to theoutside perimeter shape defined, looking at either the inlet end or theoutlet end of the media pack. Typical shapes are circular as describedin PCT WO 04/007054 and PCT application US 04/07927. Other useableshapes are obround, some examples of obround being oval shape. Ingeneral oval shapes have opposite curved ends attached by a pair ofopposite sides. In some oval shapes, the opposite sides are also curved.In other oval shapes, sometimes called racetrack shapes, the oppositesides are generally straight. Racetrack shapes are described for examplein PCT WO 04/007054 and PCT application US 04/07927.

Another way of describing the peripheral or perimeter shape is bydefining the perimeter resulting from taking a cross-section through themedia pack in a direction orthogonal to the winding axis of the coil.

Opposite flow ends or flow faces of the media pack can be provided witha variety of different definitions. In many arrangements, the ends aregenerally flat and perpendicular to one another. In other arrangements,the end faces include tapered, coiled, stepped portions which can eitherbe defined to project axially outwardly from an axial end of the sidewall of the media pack; or, to project axially inwardly from an end ofthe side wall of the media pack. Examples of such media packarrangements are shown in U.S. Provisional Application 60/578,482, filedJun. 8, 2004, incorporated herein by reference.

The flute seals (for example from the single facer bead, winding bead orstacking bead) can be formed from a variety of materials. In variousones of the cited and incorporated references, hot melt or polyurethaneseals are described as possible for various applications. Such materialsare also useable for arrangements as characterized herein.

When the media is coiled, generally a center of the coil needs to beclosed, to prevent passage of unfiltered air between the flow faces;i.e., through the media pack. Some approaches to this are referencedbelow. Others are described in U.S. Provisional 60/578,482, filed Jun.8, 2004; and U.S. Provisional 60/591,280, filed Jul. 26, 2004.

The media chosen for the corrugated sheet and facing sheet can be thesame or different. Cellulose fiber, synthetic fiber or mixed media fibermaterials can be chosen. The media can be provided with a fine fiberlayer applied to one or more surface, for example in accord with U.S.Pat. No. 6,673,136, issued Jan. 6, 2004, the complete disclosure ofwhich is incorporated herein by reference. When such material is used ononly one side of each sheet, it is typically applied on the side(s)which will form the upstream side of inlet flutes.

Above it was discussed that flow could be opposite to the directionshown in FIG. 19. An example is shown in FIG. 24.

In FIG. 24, a schematic depiction of media useable in such z-filtermedia packs as shown. The schematic depiction of FIG. 24 is generic, andis not meant to indicate unique or preferred seal type or flute shapes.

Referring to FIG. 24, the reference numeral 300 generally indicates asingle facer comprising corrugated sheet 301 secured to flat sheet 302.It is noted that the flat sheet 302 does not have to be perfectly flat,it may comprise a sheet that itself has very small corrugations andother formations therein.

Particular single facer 300 depicted, could be coiled around itself oraround a core and then around itself, typically with flat sheet 302 tothe outside. For the arrangement shown, edge 310 will form the inletface in the eventual media pack and end or edge 311 will form the outletflow faces. Thus arrows 312 represent inlet arrows and arrows 313represent outlet flow arrows. Sheet 315 is merely meant to schematicallyrepresent a flat sheet corresponding to sheet 302, of the next wind.

Adjacent edge 311 is provided a single facer seal arrangement 320. Inthis instance the single facer shield arrangement 320 comprises a beadof sealant 321 between corrugated sheet 301 and flat sheet 302,positioned along edge 310 or within about 10% of the total length of theflutes, i.e., the distance between inlet edge 310 and outlet edge 311. Avariety of materials and arrangements can be used for the sealarrangement 320. The seal arrangement could comprise a corrugated orfolded arrangement, sealed with a sealant, or sealed by other means. Theparticular seal arrangement 320 depicted, could comprise a bead of hotmelt sealant, although alternatives are possible. The seals at 320 couldbe darted or folded, as shown for FIGS. 4 and 10.

Adjacent end 310 a winding seal 330 is depicted. Winding seal 330generally provides for a seal between layers adjacent edge 311, as thesingle facer 300 is coiled. Preferably winding seal 330 is positionedwithin 10% of the total length of the flutes (i.e., the distance betweenedge 311 and 310) of edge 310.

If is the very ends (lead and tail) of the single facer need to besealed between the corrugated and flat sheets, sealant can be applied atthese locations to do so.

G. General Background Regarding Air Cleaner Systems

The principles and arrangements described in US Publ. 2005/0166561 andPCT WO 05/63361 are useable in a variety of systems. One particularsystem is depicted schematically in FIG. 25, generally at 650. In FIG.25, equipment 652, such as a vehicle 652 a having an engine 653 withsome defined rated air flow demand, for example in the range of 50 cfmto 2000 cfm (cubic feet per minute) (i.e., 1.4-57 cubic meters/minute)is shown schematically. Although alternatives are possible, theequipment 652 may, for example, comprise a bus, an over-the-highwaytruck, an off-road vehicle, a tractor, a light-duty or medium-dutytruck, or a marine vehicle such as a power boat. The engine 653 powersthe equipment 652 upon fuel combustion. In FIG. 25, air flow is showndrawn into the engine 653 at an air intake at region 655. An optionalturbo 656 is shown in phantom, as optionally boosting the air intake tothe engine 653. The turbo 656 is shown downstream from an air cleaner660, although alternate arrangement are possible.

The air cleaner 660 has a filter cartridge 662 and is shown in the airinlet stream to the engine 653. In general, in operation, air is drawnin at arrow 664 into the air cleaner 660 and through the filtercartridge 662. Upon passage through the air cleaner 660, selectedparticles and contaminants are removed from the air. The cleaned airthen flows downstream at arrow 666 into the intake 655. From there, theair flow is directed into the engine 653.

In a typical air cleaner 660, the filter cartridge 662 is a serviceablecomponent. That is, the cartridge 662 is removable and replaceablewithin the air cleaner 660. This allows the cartridge 662 to beserviced, by removal and replacement, with respect to remainder of aircleaner 660, when the cartridge 662 becomes sufficiently loaded withdust or other contaminant, to require servicing.

III. An Example Filter Cartridge in Accord with U.S. Pat. No. 6,150,432and EP 1 159 052 FIGS. 26-27

In U.S. Pat. No. 6,150,432 and EP 1 159 052, an earlier variation of thez-filter cartridge was described. One such example is shown herein inFIG. 26 at reference numeral 700. The air filter cartridge 700 comprisesa media pack 701 with opposite ends 702, 703. The media pack isgenerally in accord with the media pack 2 previously discussed anddescribed. At end 703 a seal arrangement 704 is positioned comprisingpreform 705 and molded in place seal member 706. The preform 705includes a cross-piece arrangement 708 which provides: radial strengthto the structure of the preform 705; and, inhibition against telescopingof the media at face 703.

A typical air flow direction is indicated at arrows 710. In FIG. 27, aportion of the seal arrangement 704 is shown in cross-section. Thisportion of the seal arrangement comprises support 720 andmolded-in-place seal member 706. The seal arrangement 706 includes anouter surface 706 o, with the stepped radial seal area 706 s; a thickestportion being represented at 706 b, comprising the region of greatestcompression during sealing. Structure 720 is a support to the radialseal 706 and projects axially outwardly from media pack end 703, FIG.26, in a direction away from the media pack 701. Referring to FIG. 27,outwardly directed skirt 721, extends between support 720 and an outerrim 722 (FIG. 26) of the preform 705, which fits around an outerperiphery of the media pack 701. The media pack 701 can be glued orotherwise adhesively secured to the preform 705. The seal 706 wouldtypically be premolded on the preform 704, in particular on support 720,before the preform 705 (comprising support 720, frame 708, skirt 721 andrim 722) is attached to the media pack 701, for example, adhesive.

The seal member 706 would operate similarly to those described above,but without the advantages of the overmolded portion of the seal member.

The type of seal arrangement described in connection with FIGS. 26 and27 can be applied on a variety of shapes of cartridges. The exampleshown in FIGS. 26 and 27 is a media pack 701 which is generallycylindrical in shape and has a circular cross-section. The same type ofseal can be provided on an oval shaped arrangement, such as for examplea racetrack arrangement, if desired. This is described in U.S. Pat. No.6,190,432 and EP 1 159 052 incorporated herein by reference.

Media pack 701 can generally be in accord with the descriptions hereinabove, and can be made in accord with the descriptions herein above.

IV. Selected Modifications of the Housing Seal Arrangements Shown andDescribed in FIGS. 1, 3, 4, 7, 9, 10, 26 and 27 A. A Modified HousingSeal Profile FIGS. 28-31

In FIGS. 28-31, a modified housing seal profile from those described inFIGS. 1, 3, 4, 7, 9, 10, 26 and 27, is presented. A commonality amongthe housing seals of FIGS. 1, 3, 4, 7, 9, 10, 26 and 27, is that theseal region is a stepped region, in each instance showing a total ofthree steps between an outer tip and a thickest part of the seal. Insome instances, the amount of force needed to install an element havinga seal profile in accord with FIGS. 1, 3, 4, 7, 9, 10, 26 and 27, can beundesirable. To provide for reduction in this force, a variation in thehousing seal profile of these FIGS. is provided herein. Themodifications described can be applied on a variety of perimeter shapesof seals and media packs including, for example, ones having a circularmedia pack and seal outer periphery (perimeter); and, ones having amedia pack and seal of oval, for example racetrack, outer periphery(perimeter). This will be understood from the following.

In FIGS. 28-31, only the molded seal member itself is depicted. That is,the seal member is shown schematically, without the preform member onwhich it is mounted in use being present. It should be understood thatthe preform member can be in accord with those previously described inFIGS. 1-27, or in accord with the improvements described herein below,in connection with FIGS. 32-40.

In typical arrangements, the seal member 800, FIG. 28, would not existseparately from the preform on which it is mounted. Rather the sealmember 800 would typically be molded-in-place on a preform with which itwould be used.

The seal member 800, FIG. 28, can be provided in the form of a sealmember otherwise in accord with FIGS. 26, 27, which is molded onto apreform that is attached (adhered) to a media pack; or in accord withFIGS. 1, 3, 4, 7, 9 and 10, that is molded as part of an overmold withportion thereof providing for attachment of the housing seal member andsupport, to a media pack, by an adhesive separate from the seal member.In FIGS. 28-30, an example is shown in which the housing seal member isin a form as it would be if molded-in-place on support 720, FIG. 27.

In FIG. 31 a similar housing seal profile is shown, as a portion of aseal member molded in the form of an overmold, such as in FIGS. 1, 3, 4,7, 9 and 10. In the arrangement of FIG. 31, the seal member would be anintegral part of an overmold that also secures the seal member andpreform to a media pack.

Attention is now directed to FIG. 28. In FIG. 28, reference numeral 800indicates the housing seal member. Seal member 800 is shown with acircular perimeter shape, but could be formed with alternate perimetershapes such as oval, an example being racetrack.

In FIG. 29, housing seal member 800 is depicted in cross-section.Housing seal member 800 includes an outer seal portion 801. The outerseal portion 801 is a portion which compresses to form a housing sealbetween an outer annular housing portion (when installed), and a supportsuch as support 720. Outer portion 801 includes a single, chamfered orbeveled, forward edge region 803. The chamfered or beveled forward edgeregion 803 is discussed in greater detail below.

The term “single” as used in the context of the previous paragraph, ismeant to refer an outer portion 801 that includes only one beveledregion 803 between a thick part 801 t of the radial seal region 801 thatoverlaps a support (for example support 720), and tip 805. This isdifferent from previous arrangements discussed in connection with FIGS.1, 3, 4, 7, 9, 10, 26 and 27, in which two, small, spaced, beveledregions, forming several steps, are positioned.

Still referring to FIG. 29, housing seal member 800 further includes tip805 and inner region 807. The inner region 807 would be positionedagainst an inside surface of a support, such as support 720, FIG. 27,when housing seal member 800 is used. Alternately stated, inner portion807 is positioned on an opposite side of a support from region 801,during use. Tip 805 extends between regions 807 and 801, typically overan outermost tip, remote from media pack, of a support on which housingseal member 800 is positioned in use.

Attention is now directed to FIG. 30, in which a portion of FIG. 29 isshown in an enlarged fragmentary view. Instead of possessing multiplesteps, as do the seal profiles of the arrangement shown in FIGS. 1, 3,4, 7, 9, 10, 26 and 27, housing seal member 800 includes, at outerportion 801, a single beveled or chamfered edge 803 extending betweentip 805 and outer surface 810 of region 801, which is the thickestportion 801 t that forms an outwardly directed radial seal, backed up bya support such as support 720, in use. Edge 803 typically extends at anangle, HE, relative to a plane perpendicular (indicated at P) to airflow through a filter cartridge in use, indicated by axial arrow 820,within the range of 30° to 60°, inclusive typically 35°-55°, inclusiveusually 40°-50°, inclusive. (In some instance air flow could be in adirection opposite to arrow 820, but the plane perpendicular would bethe same). It is anticipated that in a typical arrangement, a cartridgeutilizing seal 800 would be installed such that air flow of filtered airfrom a media pack would be in the direction of arrow 820. The use of asingle chamfered or beveled surface 803, extending at an angle, HE, to adirection perpendicular to flute direction in a corresponding media packis advantageous for installation in certain applications.

Typically, surface 803 is straight over a distance of at least 4 mm,usually at least 6 mm, typically 6-16 mm, inclusive. Forming radiusedportions at ends 803 o and 803 i facilitates installation.

Generally speaking, region 801 would be about 6 to 18 mm thick,inclusive, at its thickest portion 801 t (in thickness from region 809,where a support would be positioned in use.) Typically the thickness isin the range of 8-14 mm, inclusive.

In FIGS. 29 and 30, example dimensions are provided to facilitateunderstanding. Alternate dimensions can be utilized, with principlesdescribed herein. The dimensions indicated in FIGS. 29 and 30 are asfollows: GA=226.5 mm; GB=194 mm; GC=5.7 mm; GD=3.0 mm radius; GE=4.0 mmradius; GF=4.0 mm radius; GG=225.7 mm; HA=20.9 mm; HB=14.9 mm; HC=6.4 mmand HD=45°.

At region 801 t, the outer surface 810 is generally parallel orapproximately parallel to central axis 827, i.e., an axis parallel withair flow through a filter cartridge in use. Angle HD, FIG. 30, is anacute angle between surfaces 803 and surface 810 in region 801 t. It istypically no greater than 60°, usually no less than 30°, often withinthe range of 35°-55°, inclusive. Usually the angle HD is within therange of 40°-50° inclusive, for example 45° as shown.

In FIG. 31, an additional housing seal arrangement 830 is depicted, withouter portion 831, inner portion 837, tip 835 and chamfered surface 833.These regions may be generally as described for example 800, FIGS. 29and 30, except region 831 is shown fragmented at 840, indicating thathousing seal arrangement 830 is a housing seal portion of an overmoldotherwise analogous to that described above in connection with FIGS. 1,3, 4, 7, 9 and 10. Thus, the principles described in connection withFIGS. 29 and 30, can also be applied for the profile of a housing sealmember in an arrangement involving an overmold to secure the housingseal member to the media pack, as described above in connection withFIGS. 1, 3, 4, 7, 9 and 10.

B. Modifications in the Preform to Define an Advantageous FilterCartridge for Selected Situations, FIGS. 32-40

The reference numeral 850, FIG. 32, indicates an alternate filtercartridge including selected improvements described herein. Theparticular filter cartridge 850 depicted includes a media pack 851 and ahousing seal arrangement 852. The media pack 851 may be generally asdescribed hereinabove, comprising z-filter media in accord with thevariations discussed. The particular media pack 851 on housing sealarrangement 852 depicted, each have a generally oval, in this instanceracetrack, shaped perimeter outer periphery, although the principlesdescribed herein can be applied in connection with media packs that havea circular perimeter (outer periphery) if desired. For the exampleshown, the housing seal 852 comprises a portion of an overmold 855,generally in accord with overmold of seal arrangements, discussed abovein connection with FIGS. 1, 3, 4, 7, 9 and 10. However the housing seal852 could be formed as a seal member molded onto a separate preformwhich is than secured to a media pack, analogously to the descriptionabove for FIGS. 26, 27. Further, the profile of region 852 can bemodified in accord with the chamfered or beveled arrangement discussedabove in connection with FIGS. 28-31.

Still referring to FIG. 32, the media pack 851 has opposite ends 850 xand 850 y. At end 850 x, the housing seal arrangement 852 is positioned.At end 850 y an optional end skirt (skid skirt) or end piece 860 ispositioned. The framepiece or end piece 860 can be used to performfunctions similar to those for framepiece 104, discussed above inconnection with FIGS. 7 and 9. It is noted that framepiece 860 isimproved relative to framepiece 104, by the provision of scallop-shapedfinger tip receiving regions 861 therein, around selected portions offramepiece 860. The scallop-shaped regions 861 facilitate handling ofcartridge 850 during installation and removal. The scallop-shapedregions 861 can be provided with undercuts at 861 a, and areparticularly useful when positioned around the curved ends of aracetrack or oval shaped media pack 851. More specifically, scallopedregions 861 are open in a direction toward the housing seal arrangementand help with removal of cartridge 850 when installed in an arrangementof the general type described in PCT/US2005/014909, incorporated hereinby reference, including a loading of the cartridge through a housingside, with a cam or ramp.

In general, certain air cleaners being developed include mass air flowsensors (MAFS) positioned relatively close to the serviceable filtercartridge, at a location downstream therefrom. In typical arrangements,in which the housing seal is positioned on a downstream end of thefilter cartridge, this means that the housing seal arrangementcomprising a preform in the molded housing seal member, are positionedrelatively near the mass air flow sensor and in air flow coming from adownstream end of the media pack. It is preferred that the housing sealarrangement be configured so as to not contribute undesirably andinconsistently to fluctuations in the air flow or mass air flow sensorreadings can be unacceptably disturbed.

It has been found that when housing seal arrangements are molded inaccord with the profiles of FIGS. 1, 3, 4, 7, 9, 10, 26 and 27, in someinstances inwardly positioned regions of molded urethane can provideundesirable levels of inconsistent flash thereby disturbing thestability of flow pass the air flow sensor an unacceptable amount. Toinhibit this, cartridge 850 is provided with a housing seal arrangementincluding a preform having a radially, inwardly directed, usuallycontinuous, seal material resin rise stop or lip therein, that, whenused in association with features in mold, reduce this issue.

With respect to this, attention is first directed to FIG. 33. In FIG.33, cartridge 850 is depicted without end piece 860, (FIG. 32) thereon.Referring to FIG. 33, housing seal arrangement 852 comprises the moldedseal member 860 and preform 861. The preform 861, except as discussedbelow, is generally analogous to preform 35, FIGS. 3, 4 and 5, andincludes: seal support 862 which extends generally axially, outwardly,from surface 850 x away from the media pack 851; skirt 863, extendingbetween the support 862 and a perimeter region of the media pack 851;and, cross pieces 864, which provides stability to surface 850 x, andalso circumferential strength to the preform 861. The particular preform861 depicted stops short of outside periphery 851 o, of media pack 851,and includes tip 865 analogous to tip 45 a, FIG. 6. (It is noted thatcross-pieces 864 define a different portion than in previously depictedarrangements, but similar functions are accommodated.)

Preform 861 includes, unlike preform 35, FIGS. 3-6, inwardly, radially,projecting stop or lip 870 located at an end support 862, generally at ajunction between support 862 and skirt 863. Projection 870, as will beseen, provides for control of rise of seal resin in region 875, duringfilter cartridge manufacture. This can help create a more uniform regionof molded material in overlap with surface 850 x, to reduce productionof instability into air flow therefrom. In this context the term“inwardly” and variants thereof, is meant to indicate a direction ofextension away from support 862 in a direction also away from a sealregion of the molded seal member 860. The term “radially” is meant toindicate a direction of extension generally toward a central axisextending through the media pack 851.

FIG. 34, cross-sectional view analogous of FIG. 33, is depicted, exceptthrough a shorter axis of the oval shape. Features depicted haveanalogous function and are numbered accordingly.

In FIG. 35 a portion of FIG. 34 is shown in enlarged, fragmentary view.The portion depicted in FIG. 35, generally provides an understanding ofthe housing seal arrangement 852.

Referring to FIG. 35, housing seal arrangement 852 includes molded sealregion 855 having a radially, outwardly, directed housing seal surface852 s thereon and formed integrally therewith. The housing sealarrangement 852 further includes preform 861 having support 862, skirt863 and lip or projection 870. Referring to FIG. 35, at region 871, itcan be understood that projection 870 comprises an angled inner surfaceadjacent an inner surface 862 i of support 862, typically extending atan angle A1, thereto, within the range is 130° to 155°, typically 135°to 150°.

In the example shown in FIG. 35, surface 821 i extends slightlyoutwardly, in extension between joint 821 x and tip 821 y, at an angle,relative to a direction parallel with air flow through media pack 851,of about 6°, although variations are possible.

Still referring to FIG. 35, molded overmold 855 includes outer portion880 and inner portion 881. Surface 871 is provided to cap the mold inthe region where inner portion 881 rises, during molding. With respectto this, it is noted that the arrangement of FIG. 35 will be formedanalogously to the arrangement of FIGS. 1, 3, 4, 7, 9 and 10, and thuswould be inverted relative to FIG. 35, when region 881 and 880 areformed.

Still referring to FIG. 35, region 881 will typically be at least about1 mm thick, typically at least about 1.5 mm thick and usually within theranges about 1.6-2.5 mm thick, inclusive, in extension along surface 821i and inwardly therefrom, although variations from this are possible.

Region 821 i includes beveled tip 821 t, adjacent projection 870.

Projection to lip 870 then typically extends a distance of at least 1mm, usually at least 1.5 mm and typically a distance within the range ofat least 1.6-2.6 mm, although variations are possible. In a completedcartridge 850, lip 870 is positioned between tip 821 t, and the media851 g with lip 870 adjacent the seal material in region 821 i and spacedfrom the media 851.

Still referring to FIG. 35, when inverted it will be understood thatprojection 870 extends over a mold region in which resin can rise toform molded portion 881, of overmold 852, along an inside of support862. By resting on a mold cavity, region 870 will cap the rise of resinforming region 881. Thus extra flash outwardly, or uneven molding, isreduced. This will facilitate stable air flow and mass air flow sensoroperation.

In FIG. 36, preform 861 is depicted. Support 862, skirt 863 and crosspieces 864 are viewable. FIG. 37 is a cross-sectional view taken alongline 37-37, FIG. 36. Here radially inwardly directed, projection or lip870 can be viewed. It is noted that ridge or stop 870 is supported bygussets 870 a. In typical arrangement, lip 870 is radially continuous,around its entire extension, and does not include gaps therein.

FIG. 38 is a cross-sectional view taken along line 38-38, FIG. 36.

In FIG. 39 a cross-sectional view taken along line 39-39, FIG. 36 isdepicted. In FIG. 39 preform 861 is depicted inverted, as it would bewhen positioned when in a mold, for forming molded in place sealarrangement 860, FIG. 33. It can be seen that radially inwardlyprojecting stop or ridge 870 is positioned to provide a stop to resinflow upwardly along region 862 i, during molding.

FIG. 40 is a viewable molded seal region 860 when made using a preform861, in accord with a molded process generally otherwise in accord withthat described above for FIGS. 11-16. Typically molded seal region 860would not be formed separately from preform support, but rather would bemolded in place thereon. However, in FIG. 40 is depicted separately, sofeatures can be readily seen.

At 880, a surface which defines tip 821 t, resulting from rise into stop870, FIGS. 37-39, is shown. Surface 880 will typically be beveled toextend downwardly, in extension out from gap 881, FIG. 40, in which aseal support will be positioned in use.

It will be understood that a lip analogous to lip 870 can be used alsoon preform used in the arrangements of FIGS. 26, 27, to control risealong an inner region while the mold in place seal arrangements usedtherein, are formed. The principal difference is that such sealarrangements do not include the overmold region 890, FIG. 40.

In FIGS. 32-40, example dimension are provided for an examplearrangement utilizing a racetrack shape. The example dimensions are asfollows: IA=300.4 mm; IB=310.3 mm; JA=300.4 mm; JB=190 mm; JC=221.1 mm;JD=299 mm; KA=152.4 mm; KB=151 mm; LA=295.6 mm; LB=70°; LC=49.5 mm;LD=24.7 mm; LE=147.6 mm; LF=61.8 mm radius; LG=2 mm; LH=5.0 mm diameter;MA=276.6 mm; MB=2.5 mm; MC=271.6 mm; MD=15.8 mm; ME=27 mm; MF=295.6 mm;NA=128.6 mm; NB=123.6 mm; NC=15.8 mm; ND=147.6 mm; OA=147.6 mm; OB=15.8mm; OC=125.2 mm; OD=130.2 mm; PA=300.4 mm; PB=28.6°; PC=295.6 mm; PD=4.0mm radius; PE=269.1 mm; PF=150.8°; PG=25°; PH=271.4 mm; PI=33.3°; PJ=4.2mm; and PK=304 mm.

1-19. (canceled)
 20. A filter element comprising: (a) a media packincluding a first flow face and an opposite second flow face, an axialdirection extending from the first flow face to the second flow face,and a periphery extending between the first flow face and the secondflow face; the media pack defining: (i) a plurality of flutes extendingin an axial direction from the first flow face to the second flow face;(b) a first end piece comprising a housing seal support section, and amedia face cross-piece arrangement, wherein: (i) the housing sealsupport section extends axially away from the first flow face in adirection away from the media pack; (ii) the housing seal supportsection includes a radially outwardly facing surface and a radiallyinwardly facing surface; and (ii) the media face cross-piece arrangementextends across the first flow face; (c) an overmold formed of a sealingmaterial having: (i) a first portion sealing an interface between thefirst end piece and the media pack, and extending from the first flowface toward the second flow face over the periphery of the media pack;(ii) a second portion oriented to form an air cleaner seal, between thefilter element and an air cleaner, in use; (iii) the second portionbeing located along the radially outwardly facing surface of the housingseal support section; and (iii) the first and second portions of theovermold being integral with one another; and (d) a second end piecearranged around the periphery of the media pack, wherein: (i) the secondend piece is spaced from the first end piece; (ii) the second end pieceincludes projections that extend over the media pack second flow face;and (iii) the second end piece comprising a plurality of undercutsfacing toward the overmold of a sealing material.
 21. A filter elementaccording to claim 20 wherein: (a) the media pack comprises a stackedmedia pack.
 22. A filter element according to claim 20 wherein: (a) noportion of the first end piece extends around the periphery of the mediapack.
 23. A filter element according to claim 20 wherein: (a) a portionof the first end piece extends around the periphery of the media pack.24. A filter element according to claim 23 wherein: (a) the first endpiece comprises a media engagement periphery, and the media engagementperiphery is the portion of the first end piece that extends around theperiphery of the media pack.
 25. A filter element according to claim 20wherein: (a) the first portion sealing the interface between the firstend piece and the media pack extends at least 8 mm from the first flowface toward the second flow face over the periphery of the media pack.26. An air filter cartridge according to claim 20 wherein: (a) the mediapack comprises two, opposite, generally straight sides.
 27. An airfilter cartridge according to claim 20 wherein: (a) the media pack has acircular cross-section.
 28. An air filter cartridge according to claim20 wherein: (a) the media pack has a racetrack shaped cross-section. 29.An air filter cartridge according to claim 20 wherein: (a) the mediapack comprises alternating fluted media secured to facing media.
 30. Anair filter cartridge according to claim 27 wherein: (a) the secondportion of the overmold is configured to form an outwardly directedradial seal.
 31. An air filter cartridge according to claim 20 wherein:(a) a portion of the first end piece helps contain flow of the overmoldfrom extending across the media pack first flow face.
 32. An air filtercartridge according to claim 20 wherein: (a) wherein the radiallyinwardly facing portion of the housing seal support section includes aportion free of the overmold thereon.
 33. An air filter cartridgeaccording to claim 20 wherein: (a) at least a portion of the pluralityof flutes do not extend a complete distance between the first flow faceand the second flow face.
 34. An air filter cartridge according to claim33 wherein: (a) the at least a portion of the plurality of flutes areclosed prior to one of the first flow face and the second flow face. 35.An air filter cartridge according to claim 34 wherein: (a) the flutesclosed prior to one of the first flow face and the second flow face areclosed by folding the flutes closed.
 36. An air filter cartridgeaccording to claim 29 wherein: (a) the alternating fluted media andfacing media comprises straight flutes.
 37. An air filter cartridgeaccording to claim 29 wherein: (a) the alternating fluted media andfacing media comprises non-straight flutes.
 38. An air filter cartridgeaccording to claim 20 wherein: (a) the media pack first flow facecomprises an outlet flow face.